wakeup-from-suspend and system_wakeup changes
v10 cover wakeup-from-suspend and system_wakeup changes
Changes in v10:
- added qemu_register_wakeup_support call in hw/i386/xen/xen-hvm.c
- explained the effects of not checking the query-current-machine before issuing guest-suspend-ram/hybrid in QGA documentation
- changed qemu_system_wakeup_request to allow the runstate check error to be propagated to callers
- previous series link:
https://lists.gnu.org/archive/html/qemu-devel/2018-09/msg02171.html
Daniel Henrique Barboza (3):
qmp: query-current-machine with wakeup-suspend-support
qga: update guest-suspend-ram and guest-suspend-hybrid descriptions qmp hmp: Make system_wakeup check wake-up support and run state
hmp.c | 5 ++++- hw/acpi/core.c | 10 +++++++++- hw/char/serial.c | 3 ++- hw/i386/xen/xen-hvm.c | 5 +++++ hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 4 +++- migration/migration.c | 7 +++++-- qapi/misc.json | 32 +++++++++++++++++++++++++++++++- qga/qapi-schema.json | 16 ++++++++++------ qmp.c | 13 ++++++++++++- vl.c | 23 ++++++++++++++++++++++- 12 files changed, 111 insertions(+), 19 deletions(-)
Signature · 1 line
2.19.1
PATCH v10 1/3 qmp: query-current-machine with wakeup-suspend-support
When issuing the qmp/hmp 'system_wakeup' command, what happens in a nutshell is:
- qmp_system_wakeup_request set runstate to RUNNING, sets a wakeup_reason and notify the event
- in the main_loop, all vcpus are paused, a system reset is issued, all subscribers of wakeup_notifiers receives a notification, vcpus are then resumed and the wake up QAPI event is fired
Note that this procedure alone doesn't ensure that the guest will awake from SUSPENDED state - the subscribers of the wake up event must take action to resume the guest, otherwise the guest will simply reboot. At this moment, only the ACPI machines via acpi_pm1_cnt_init has wake-up from suspend support.
However, only the presence of 'system_wakeup' is required for QGA to support 'guest-suspend-ram' and 'guest-suspend-hybrid' at this moment. This means that the user/management will expect to suspend the guest using one of those suspend commands and then resume execution using system_wakeup, regardless of the support offered in system_wakeup in the first place.
This patch creates a new API called query-current-machine [1], that holds a new flag called 'wakeup-suspend-support' that indicates if the guest supports wake up from suspend via system_wakeup. The machine is considered to implement wake-up support if a call to a new 'qemu_register_wakeup_support' is made during its init, as it is now being done inside acpi_pm1_cnt_init. This allows for any other machine type to declare wake-up support regardless of ACPI state or wakeup_notifiers subscription, making easier for newer implementations that might have its own mechanisms in the future.
This is the expected output of query-current-machine when running a x86 guest:
{"execute" : "query-current-machine"}
{"return": {"wakeup-suspend-support": true}}
Running the same x86 guest, but with the --no-acpi option:
{"execute" : "query-current-machine"}
{"return": {"wakeup-suspend-support": false}}
This is the output when running a pseries guest:
{"execute" : "query-current-machine"}
{"return": {"wakeup-suspend-support": false}}
With this extra tool, management can avoid situations where a guest that does not have proper suspend/wake capabilities ends up in inconsistent state (e.g.
https://github.com/open-power-host-os/qemu/issues/31).
[1] the decision of creating the query-current-machine API is based on discussions in the QEMU mailing list where it was decided that query-target wasn't a proper place to store the wake-up flag, neither was query-machines because this isn't a static property of the machine object. This new API can then be used to store other dynamic machine properties that are scattered around the code ATM. More info at:
https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg04235.html
--- hw/acpi/core.c | 6 ++++++ hw/i386/xen/xen-hvm.c | 5 +++++ include/sysemu/sysemu.h | 1 + qapi/misc.json | 24 ++++++++++++++++++++++++ vl.c | 19 +++++++++++++++++++ 5 files changed, 55 insertions(+)
hw/acpi/core.c +6 -0
@@ -617,6 +617,12 @@ void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent, ar->pm1.cnt.s4_val = s4_val; ar->wakeup.notify = acpi_notify_wakeup;qemu_register_wakeup_notifier (&ar->wakeup); + +/* +* Register wake-up support in QMP query-current-machine API +*/ +qemu_register_wakeup_support (); +memory_region_init_io (&ar->pm1.cnt.io,memory_region_owner (parent), &acpi_pm_cnt_ops, ar,"acpi-cnt" ,2 );memory_region_add_subregion (parent,4 , &ar->pm1.cnt.io);
hw/i386/xen/xen-hvm.c +5 -0
@@ -1405,6 +1405,11 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory) state->wakeup.notify = xen_wakeup_notifier;qemu_register_wakeup_notifier (&state->wakeup); +/* +* Register wake-up support in QMP query-current-machine API +*/ +qemu_register_wakeup_support (); + rc =xen_map_ioreq_server (state);if (rc <0 ) { goto err;
include/sysemu/sysemu.h +1 -0
@@ -77,6 +77,7 @@ void qemu_register_suspend_notifier(Notifier *notifier);void qemu_system_wakeup_request (WakeupReason reason);void qemu_system_wakeup_enable (WakeupReason reason,bool enabled);void qemu_register_wakeup_notifier (Notifier *notifier); +void qemu_register_wakeup_support (void );void qemu_system_shutdown_request (ShutdownCause reason);void qemu_system_powerdown_request (void );void qemu_register_powerdown_notifier (Notifier *notifier);
qapi/misc.json +24 -0
@@ -2008,6 +2008,30 @@ ## { 'command': 'query-machines', 'returns': ['MachineInfo'] } +## +# @CurrentMachineParams: +# +# Information describing the running machine parameters. +# +# @wakeup-suspend-support: true if the machine supports wake up from +# suspend +# +# Since: 3.2.0 +## +{ 'struct': 'CurrentMachineParams', + 'data': { 'wakeup-suspend-support': 'bool'} } + +## +# @query-current-machine: +# +# Return information on the current virtual machine. +# +# Returns: CurrentMachineParams +# +# Since: 3.2.0 +## +{ 'command': 'query-current-machine', 'returns': 'CurrentMachineParams' } + ## # @CpuDefinitionInfo: #
vl.c +19 -0
@@ -191,6 +191,7 @@ bool boot_strict;uint8_t *boot_splash_filedata;size_t boot_splash_filedata_size;uint8_t qemu_extra_params_fw[2 ]; +bool wakeup_suspend_enabled;int icount_align_option;
@@ -1782,6 +1783,24 @@ void qemu_register_wakeup_notifier(Notifier *notifier)notifier_list_add (&wakeup_notifiers, notifier); } +void qemu_register_wakeup_support (void ) +{ + wakeup_suspend_enabled = true; +} + +static bool qemu_wakeup_suspend_enabled (void ) +{ +return wakeup_suspend_enabled; +} + +CurrentMachineParams *qmp_query_current_machine (Error **errp) +{ +CurrentMachineParams *params =g_malloc0 (sizeof (*params)); + params->wakeup_suspend_support =qemu_wakeup_suspend_enabled (); + +return params; +} +void qemu_system_killed (int signal,pid_t pid) { shutdown_signal = signal;
Signature · 1 line
2.19.1
Re: [Qemu-devel] [PATCH for-3.2 v10 1/3] qmp: query-current-machine with wakeup-suspend-support
Quoted 9 lines · Daniel Henrique Barboza
When issuing the qmp/hmp '
system_wakeup' command, what happens in a nutshell is:-
qmp_system_wakeup_requestset runstate to RUNNING, sets awakeup_reasonand notify the event
- in themain_loop, all vcpus are paused, a system reset is issued, all subscribers ofwakeup_notifiersreceives a notification, vcpus are then resumed and the wake up QAPI event is fired
Quoted 5 lines
Note that this procedure alone doesn't ensure that the guest will awake from SUSPENDED state - the subscribers of the wake up event must take action to resume the guest, otherwise the guest will simply reboot. At this moment, only the ACPI machines via
acpi_pm1_cnt_inithas wake-up from suspend support.
the ACPI machines via acpi_pm1_cnt_init have
Quoted 7 lines
However, only the presence of '
system_wakeup' is required for QGA to support 'guest-suspend-ram' and 'guest-suspend-hybrid' at this moment. This means that the user/management will expect to suspend the guest using one of those suspend commands and then resume execution usingsystem_wakeup, regardless of the support offered insystem_wakeupin the first place.
Quoted 5 lines
This patch creates a new API called query-current-machine [1], that holds a new flag called 'wakeup-suspend-support' that indicates if the guest supports wake up from suspend via
system_wakeup. The machine is considered to implement wake-up support if a call to a new 'qemu_register_wakeup_support' is made during its init, as it is now being done insideacpi_pm1_cnt_init.
In xen_hvm_init(), too.
Doesn't that contradict "only the ACPI machines via acpi_pm1_cnt_init has wake-up from suspend support"?
Quoted 3 lines
This allows for any other machine type to declare wake-up support regardless of ACPI state or
wakeup_notifierssubscription, making easier for newer implementations that might have its own mechanisms in the future.
their own mechanisms
Quoted 46 lines
This is the expected output of query-current-machine when running a x86 guest:
{"execute" : "query-current-machine"}
{"return": {"wakeup-suspend-support": true}}Running the same x86 guest, but with the --no-acpi option:
{"execute" : "query-current-machine"}
{"return": {"wakeup-suspend-support": false}}This is the output when running a pseries guest:
{"execute" : "query-current-machine"}
{"return": {"wakeup-suspend-support": false}}With this extra tool, management can avoid situations where a guest that does not have proper suspend/wake capabilities ends up in inconsistent state (e.g.
https://github.com/open-power-host-os/qemu/issues/31).[1] the decision of creating the query-current-machine API is based on discussions in the QEMU mailing list where it was decided that query-target wasn't a proper place to store the wake-up flag, neither was query-machines because this isn't a static property of the machine object. This new API can then be used to store other dynamic machine properties that are scattered around the code ATM. More info at:
https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg04235.htmlReported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hw/acpi/core.c | 6 ++++++ hw/i386/xen/xen-hvm.c | 5 +++++ include/sysemu/sysemu.h | 1 + qapi/misc.json | 24 ++++++++++++++++++++++++ vl.c | 19 +++++++++++++++++++ 5 files changed, 55 insertions(+)hw/acpi/core.c +0
-0
hw/acpi/core.c void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent, · line 625
Quoted 9 lines
hw/acpi/core.c +6
-0@@ -617,6 +617,12 @@ void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent, ar->pm1.cnt.s4_val = s4_val; ar->wakeup.notify = acpi_notify_wakeup;qemu_register_wakeup_notifier (&ar->wakeup); + +/* +* Register wake-up support in QMP query-current-machine API +*/ +qemu_register_wakeup_support (); +
Not sure we really need the comment. Up to the maintainer.
Quoted 8 lines
hw/acpi/core.c +0
-0memory_region_init_io (&ar->pm1.cnt.io,memory_region_owner (parent), &acpi_pm_cnt_ops, ar,"acpi-cnt" ,2 );memory_region_add_subregion (parent,4 , &ar->pm1.cnt.io);hw/i386/xen/xen-hvm.c +0
-0
hw/i386/xen/xen-hvm.c void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory) · line 1412
Quoted 8 lines
hw/i386/xen/xen-hvm.c +5
-0@@ -1405,6 +1405,11 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory) state->wakeup.notify = xen_wakeup_notifier;qemu_register_wakeup_notifier (&state->wakeup); +/* +* Register wake-up support in QMP query-current-machine API +*/ +qemu_register_wakeup_support (); +
Likewise.
Quoted 22 lines
hw/i386/xen/xen-hvm.c +0
-0rc =xen_map_ioreq_server (state);if (rc <0 ) { goto err;include/sysemu/sysemu.h +1
-0@@ -77,6 +77,7 @@ void qemu_register_suspend_notifier(Notifier *notifier);void qemu_system_wakeup_request (WakeupReason reason);void qemu_system_wakeup_enable (WakeupReason reason,bool enabled);void qemu_register_wakeup_notifier (Notifier *notifier); +void qemu_register_wakeup_support (void );void qemu_system_shutdown_request (ShutdownCause reason);void qemu_system_powerdown_request (void );void qemu_register_powerdown_notifier (Notifier *notifier);qapi/misc.json +0
-0@@ -2008,6 +2008,30 @@ ## { 'command': 'query-machines', 'returns': ['MachineInfo'] }
qapi/misc.json line 2019
Quoted 10 lines
qapi/misc.json +9
-0+## +# @CurrentMachineParams: +# +# Information describing the running machine parameters. +# +# @wakeup-suspend-support: true if the machine supports wake up from +# suspend +# +# Since: 3.2.0
The next release is going to be named 4.0. Perhaps the maintainer can fix that up for you.
Quoted 45 lines
qapi/misc.json +15
-0+## +{ 'struct': 'CurrentMachineParams', + 'data': { 'wakeup-suspend-support': 'bool'} } + +## +# @query-current-machine: +# +# Return information on the current virtual machine. +# +# Returns: CurrentMachineParams +# +# Since: 3.2.0 +## +{ 'command': 'query-current-machine', 'returns': 'CurrentMachineParams' } + ## # @CpuDefinitionInfo: #vl.c +12
-0@@ -191,6 +191,7 @@ bool boot_strict;uint8_t *boot_splash_filedata;size_t boot_splash_filedata_size;uint8_t qemu_extra_params_fw[2 ]; +bool wakeup_suspend_enabled;int icount_align_option;@@ -1782,6 +1783,24 @@ void qemu_register_wakeup_notifier(Notifier *notifier)notifier_list_add (&wakeup_notifiers, notifier); } +void qemu_register_wakeup_support (void ) +{ + wakeup_suspend_enabled = true; +} + +static bool qemu_wakeup_suspend_enabled (void ) +{ +return wakeup_suspend_enabled; +} + +CurrentMachineParams *qmp_query_current_machine (Error **errp)
vl.c void qemu_register_wakeup_notifier(Notifier *notifier) · line 1806
Quoted 10 lines
vl.c +7
-0+{ +CurrentMachineParams *params =g_malloc0 (sizeof (*params)); + params->wakeup_suspend_support =qemu_wakeup_suspend_enabled (); + +return params; +} +void qemu_system_killed (int signal,pid_t pid) { shutdown_signal = signal;
Patch looks good to me.
PATCH v10 2/3 qga: update guest-suspend-ram and guest-suspend-hybrid descriptions
In reply to Daniel Henrique BarbozaThis patch updates the descriptions of 'guest-suspend-ram' and 'guest-suspend-hybrid' to mention that both commands relies now on the proper support for wake up from suspend, retrieved by the 'wakeup-suspend-support' attribute of the 'query-current-machine' QMP command.
--- qga/qapi-schema.json | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
qga/qapi-schema.json +10 -6
@@ -567,9 +567,11 @@ # For the best results it's strongly recommended to have the pm-utils # package installed in the guest. # -# IMPORTANT: guest-suspend-ram requires QEMU to support the 'system_wakeup' -# command. Thus, it's *required* to query QEMU for the presence of the -# 'system_wakeup' command before issuing guest-suspend-ram. +# IMPORTANT: guest-suspend-ram requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to +# awaken, forcing the user to power cycle the guest to bring it back. # # This command does NOT return a response on success. There are two options # to check for success:
@@ -594,9 +596,11 @@ # # This command requires the pm-utils package to be installed in the guest. # -# IMPORTANT: guest-suspend-hybrid requires QEMU to support the 'system_wakeup' -# command. Thus, it's *required* to query QEMU for the presence of the -# 'system_wakeup' command before issuing guest-suspend-hybrid. +# IMPORTANT: guest-suspend-hybrid requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to +# awaken, forcing the user to power cycle the guest to bring it back. # # This command does NOT return a response on success. There are two options # to check for success:
Signature · 1 line
2.19.1
Re: [Qemu-devel] [PATCH for-3.2 v10 2/3] qga: update guest-suspend-ram and guest-suspend-hybrid descriptions
Quoted 37 lines · Daniel Henrique Barboza
This patch updates the descriptions of 'guest-suspend-ram' and 'guest-suspend-hybrid' to mention that both commands relies now on the proper support for wake up from suspend, retrieved by the 'wakeup-suspend-support' attribute of the 'query-current-machine' QMP command.
Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>Reviewed-by Michael Roth <[email protected]>--- qga/qapi-schema.json | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)qga/qapi-schema.json +5
-4@@ -567,9 +567,11 @@ # For the best results it's strongly recommended to have the pm-utils # package installed in the guest. # -# IMPORTANT: guest-suspend-ram requires QEMU to support the 'system_wakeup' -# command. Thus, it's *required* to query QEMU for the presence of the -# 'system_wakeup' command before issuing guest-suspend-ram. +# IMPORTANT: guest-suspend-ram requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to +# awaken, forcing the user to power cycle the guest to bring it back. # # This command does NOT return a response on success. There are two options # to check for success:@@ -594,9 +596,11 @@ # # This command requires the pm-utils package to be installed in the guest. # -# IMPORTANT: guest-suspend-hybrid requires QEMU to support the 'system_wakeup'
qga/qapi-schema.json line 606
Quoted 10 lines
qga/qapi-schema.json +5
-2-# command. Thus, it's *required* to query QEMU for the presence of the -# 'system_wakeup' command before issuing guest-suspend-hybrid. +# IMPORTANT: guest-suspend-hybrid requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to +# awaken, forcing the user to power cycle the guest to bring it back. # # This command does NOT return a response on success. There are two options # to check for success:
Nice improvement. However, I'd tone down "You *must*" to "You should". This is just one of many ways to screw up the guest with the guest agent. While serious, it's not as bad as compromising the sandbox, or killing QEMU.
Re: [Qemu-devel] [PATCH for-3.2 v10 2/3] qga: update guest-suspend-ram and guest-suspend-hybrid descriptions
Quoted 45 lines · Markus Armbruster
Quoted 43 lines · Daniel Henrique Barboza
This patch updates the descriptions of 'guest-suspend-ram' and 'guest-suspend-hybrid' to mention that both commands relies now on the proper support for wake up from suspend, retrieved by the 'wakeup-suspend-support' attribute of the 'query-current-machine' QMP command.
Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>Reviewed-by Michael Roth <[email protected]>--- qga/qapi-schema.json | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)qga/qapi-schema.json +9
-6@@ -567,9 +567,11 @@ # For the best results it's strongly recommended to have the pm-utils # package installed in the guest. # -# IMPORTANT: guest-suspend-ram requires QEMU to support the 'system_wakeup' -# command. Thus, it's *required* to query QEMU for the presence of the -# 'system_wakeup' command before issuing guest-suspend-ram. +# IMPORTANT: guest-suspend-ram requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to +# awaken, forcing the user to power cycle the guest to bring it back. # # This command does NOT return a response on success. There are two options # to check for success:@@ -594,9 +596,11 @@ # # This command requires the pm-utils package to be installed in the guest. # -# IMPORTANT: guest-suspend-hybrid requires QEMU to support the 'system_wakeup' -# command. Thus, it's *required* to query QEMU for the presence of the -# 'system_wakeup' command before issuing guest-suspend-hybrid. +# IMPORTANT: guest-suspend-hybrid requires working wakeup support in +# QEMU. You *must* check QMP command query-current-machine returns +# wakeup-suspend-support: true before issuing this command. Failure in +# doing so can result in a suspended guest that QEMU will not be able to
Quoted 8 lines
qga/qapi-schema.json line 577
Quoted 4 lines
qga/qapi-schema.json +1
-0+# awaken, forcing the user to power cycle the guest to bring it back. # # This command does NOT return a response on success. There are two options # to check for success:Nice improvement. However, I'd tone down "You *must*" to "You should". This is just one of many ways to screw up the guest with the guest agent. While serious, it's not as bad as compromising the sandbox, or killing QEMU.
I'll tone down in the next spin. Thanks!
PATCH v10 3/3 qmp hmp: Make system_wakeup check wake-up support and run state
In reply to Daniel Henrique BarbozaThe qmp/hmp command 'system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' from vl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.
This means that system_wakeup is silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.
Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes qmp_system_wakeup to check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output of system_wakeup in a guest that does not have wake-up from suspend support (ppc64):
(qemu) system_wakeup
wake-up from suspend is not supported by this guest (qemu)
And this is the output of system_wakeup in a x86 guest that has the support but isn't suspended:
(qemu) system_wakeup
Unable to wake up: guest is not in suspended state (qemu)
--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)
hmp.c +4 -1
@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }void hmp_nmi (Monitor *mon,const QDict *qdict)
hw/acpi/core.c +3 -1
@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque) {ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }
hw/char/serial.c +2 -1
@@ -609,9 +609,10 @@ static int serial_can_receive1(void *opaque)static void serial_receive1 (void *opaque,const uint8_t *buf,int size) {SerialState *s = opaque; +Error *err =NULL ;if (s->wakeup) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err); }if (s->fcr &UART_FCR_FE ) {int i;
hw/input/ps2.c +6 -3
@@ -253,9 +253,10 @@ void ps2_queue_4(PS2State *s, int b1, int b2, int b3, int b4)static void ps2_put_keycode (void *opaque,int keycode) {PS2KbdState *s = opaque; +Error *err =NULL ;trace_ps2_put_keycode (opaque, keycode); -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err);if (s->translate) {if (keycode ==0xf0 ) {
@@ -276,6 +277,7 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src, {PS2KbdState *s = (PS2KbdState *)dev;InputKeyEvent *key = evt->u.key.data; +Error *err =NULL ;int qcode;uint16_t keycode =0 ;int mod;
@@ -285,7 +287,7 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src,return ; } -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err);assert (evt->type ==INPUT_EVENT_KIND_KEY ); qcode =qemu_input_key_value_to_qcode (key->key);
@@ -741,6 +743,7 @@ static void ps2_mouse_event(DeviceState *dev, QemuConsole *src,static void ps2_mouse_sync (DeviceState *dev) {PS2MouseState *s = (PS2MouseState *)dev; +Error *err =NULL ;/* do not sync while disabled to prevent stream corruption */ if (!(s->mouse_status &MOUSE_STATUS_ENABLED )) {
@@ -748,7 +751,7 @@ static void ps2_mouse_sync(DeviceState *dev) }if (s->mouse_buttons) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err); }if (!(s->mouse_status &MOUSE_STATUS_REMOTE )) {/* if not remote, send event. Multiple events are sent if
hw/timer/mc146818rtc.c +2 -1
@@ -443,6 +443,7 @@ static uint64_t get_next_alarm(RTCState *s)static void rtc_update_timer (void *opaque) {RTCState *s = opaque; +Error *err =NULL ;int32_t irqs =REG_C_UF ;int32_t new_irqs;
@@ -455,7 +456,7 @@ static void rtc_update_timer(void *opaque)if (qemu_clock_get_ns (rtc_clock) >= s->next_alarm_time) { irqs |=REG_C_AF ;if (s->cmos_data[RTC_REG_B ] ®_B_AIE ) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_RTC ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_RTC , &err); } }
include/sysemu/sysemu.h +2 -1
@@ -74,7 +74,8 @@ void qemu_exit_preconfig_request(void);void qemu_system_reset_request (ShutdownCause reason);void qemu_system_suspend_request (void );void qemu_register_suspend_notifier (Notifier *notifier); -void qemu_system_wakeup_request (WakeupReason reason); +bool qemu_wakeup_suspend_enabled (void ); +void qemu_system_wakeup_request (WakeupReason reason,Error **errp);void qemu_system_wakeup_enable (WakeupReason reason,bool enabled);void qemu_register_wakeup_notifier (Notifier *notifier);void qemu_register_wakeup_support (void );
migration/migration.c +5 -2
@@ -2390,6 +2390,8 @@ static int postcopy_start(MigrationState *ms)int64_t bandwidth =migrate_max_postcopy_bandwidth ();bool restart_block = false;int cur_state =MIGRATION_STATUS_ACTIVE ; +Error *err =NULL ; +if (!migrate_pause_before_switchover ()) {migrate_set_state (&ms->state,MIGRATION_STATUS_ACTIVE ,MIGRATION_STATUS_POSTCOPY_ACTIVE );
@@ -2399,7 +2401,7 @@ static int postcopy_start(MigrationState *ms)qemu_mutex_lock_iothread ();trace_postcopy_start_set_run (); -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err);global_state_store (); ret =vm_stop_force_state (RUN_STATE_FINISH_MIGRATE );if (ret <0 ) {
@@ -2597,13 +2599,14 @@ static int migration_maybe_pause(MigrationState *s,*/ static void migration_completion (MigrationState *s) { +Error *err =NULL ;int ret;int current_active_state = s->state;if (s->state ==MIGRATION_STATUS_ACTIVE ) {qemu_mutex_lock_iothread (); s->downtime_start =qemu_clock_get_ms (QEMU_CLOCK_REALTIME ); -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err); s->vm_was_running =runstate_is_running (); ret =global_state_store ();
qapi/misc.json +7 -1
@@ -1235,12 +1235,18 @@ ## # @system_wakeup: # -# Wakeup guest from suspend. Does nothing in case the guest isn't suspended. +# Wake-up guest from suspend. If the guest has wake-up from suspend +# support enabled (wakeup-suspend-support flag from +# query-current-machine), wake-up guest from suspend if the guest is +# in SUSPENDED state. Returns an error otherwise. # # Since: 1.1 # # Returns: nothing. # +# Note: prior to 3.2, this command does nothing in case the guest +# isn't suspended. +# # Example: # # -> { "execute": "system_wakeup" }
qmp.c +12 -1
@@ -183,7 +183,18 @@ void qmp_cont(Error **errp)void qmp_system_wakeup (Error **errp) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +Error *local_err =NULL ; + +if (!qemu_wakeup_suspend_enabled ()) { +error_setg (errp, +"wake-up from suspend is not supported by this guest" ); +return ; + } + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &local_err); +if (local_err) { +error_propagate (errp, local_err); + } }ObjectPropertyInfoList *qmp_qom_list (const char *path,Error **errp)
vl.c +4 -2
@@ -1754,11 +1754,13 @@ void qemu_register_suspend_notifier(Notifier *notifier)notifier_list_add (&suspend_notifiers, notifier); } -void qemu_system_wakeup_request (WakeupReason reason) +void qemu_system_wakeup_request (WakeupReason reason,Error **errp) {trace_system_wakeup_request (reason);if (!runstate_check (RUN_STATE_SUSPENDED )) { +error_setg (errp, +"Unable to wake up: guest is not in suspended state" );return ; }if (!(wakeup_reason_mask & (1 << reason))) {
@@ -1788,7 +1790,7 @@ void qemu_register_wakeup_support(void) wakeup_suspend_enabled = true; } -static bool qemu_wakeup_suspend_enabled (void ) +bool qemu_wakeup_suspend_enabled (void ) {return wakeup_suspend_enabled; }
Signature · 1 line
2.19.1
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
Quoted 227 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +3
-1@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque) {ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }hw/char/serial.c +2
-1@@ -609,9 +609,10 @@ static int serial_can_receive1(void *opaque)static void serial_receive1 (void *opaque,const uint8_t *buf,int size) {SerialState *s = opaque; +Error *err =NULL ;if (s->wakeup) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err); }if (s->fcr &UART_FCR_FE ) {int i;hw/input/ps2.c +6
-3@@ -253,9 +253,10 @@ void ps2_queue_4(PS2State *s, int b1, int b2, int b3, int b4)static void ps2_put_keycode (void *opaque,int keycode) {PS2KbdState *s = opaque; +Error *err =NULL ;trace_ps2_put_keycode (opaque, keycode); -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err);if (s->translate) {if (keycode ==0xf0 ) {@@ -276,6 +277,7 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src, {PS2KbdState *s = (PS2KbdState *)dev;InputKeyEvent *key = evt->u.key.data; +Error *err =NULL ;int qcode;uint16_t keycode =0 ;int mod;@@ -285,7 +287,7 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src,return ; } -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err);assert (evt->type ==INPUT_EVENT_KIND_KEY ); qcode =qemu_input_key_value_to_qcode (key->key);@@ -741,6 +743,7 @@ static void ps2_mouse_event(DeviceState *dev, QemuConsole *src,static void ps2_mouse_sync (DeviceState *dev) {PS2MouseState *s = (PS2MouseState *)dev; +Error *err =NULL ;/* do not sync while disabled to prevent stream corruption */ if (!(s->mouse_status &MOUSE_STATUS_ENABLED )) {@@ -748,7 +751,7 @@ static void ps2_mouse_sync(DeviceState *dev) }if (s->mouse_buttons) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err); }if (!(s->mouse_status &MOUSE_STATUS_REMOTE )) {/* if not remote, send event. Multiple events are sent if hw/timer/mc146818rtc.c +2
-1@@ -443,6 +443,7 @@ static uint64_t get_next_alarm(RTCState *s)static void rtc_update_timer (void *opaque) {RTCState *s = opaque; +Error *err =NULL ;int32_t irqs =REG_C_UF ;int32_t new_irqs;@@ -455,7 +456,7 @@ static void rtc_update_timer(void *opaque)if (qemu_clock_get_ns (rtc_clock) >= s->next_alarm_time) { irqs |=REG_C_AF ;if (s->cmos_data[RTC_REG_B ] ®_B_AIE ) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_RTC ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_RTC , &err); } }include/sysemu/sysemu.h +2
-1@@ -74,7 +74,8 @@ void qemu_exit_preconfig_request(void);void qemu_system_reset_request (ShutdownCause reason);void qemu_system_suspend_request (void );void qemu_register_suspend_notifier (Notifier *notifier); -void qemu_system_wakeup_request (WakeupReason reason); +bool qemu_wakeup_suspend_enabled (void ); +void qemu_system_wakeup_request (WakeupReason reason,Error **errp);void qemu_system_wakeup_enable (WakeupReason reason,bool enabled);void qemu_register_wakeup_notifier (Notifier *notifier);void qemu_register_wakeup_support (void );migration/migration.c +5
-2@@ -2390,6 +2390,8 @@ static int postcopy_start(MigrationState *ms)int64_t bandwidth =migrate_max_postcopy_bandwidth ();bool restart_block = false;int cur_state =MIGRATION_STATUS_ACTIVE ; +Error *err =NULL ; +if (!migrate_pause_before_switchover ()) {migrate_set_state (&ms->state,MIGRATION_STATUS_ACTIVE ,MIGRATION_STATUS_POSTCOPY_ACTIVE );@@ -2399,7 +2401,7 @@ static int postcopy_start(MigrationState *ms)qemu_mutex_lock_iothread ();trace_postcopy_start_set_run (); -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err);global_state_store (); ret =vm_stop_force_state (RUN_STATE_FINISH_MIGRATE );if (ret <0 ) {@@ -2597,13 +2599,14 @@ static int migration_maybe_pause(MigrationState *s,*/ static void migration_completion (MigrationState *s) { +Error *err =NULL ;int ret;int current_active_state = s->state;if (s->state ==MIGRATION_STATUS_ACTIVE ) {qemu_mutex_lock_iothread (); s->downtime_start =qemu_clock_get_ms (QEMU_CLOCK_REALTIME ); -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &err); s->vm_was_running =runstate_is_running (); ret =global_state_store ();qapi/misc.json +0
-0
qapi/misc.json line 1240
Quoted 7 lines
qapi/misc.json +3
-1@@ -1235,12 +1235,18 @@ ## # @system_wakeup: # -# Wakeup guest from suspend. Does nothing in case the guest isn't suspended. +# Wake-up guest from suspend. If the guest has wake-up from suspend +# support enabled (wakeup-suspend-support flag from +# query-current-machine), wake-up guest from suspend if the guest is
"wake up guest", because wake-up is the noun, the verb is spelled wake up.
qapi/misc.json line 1241
Quoted 1 line
qapi/misc.json +1
-0+# in SUSPENDED state. Returns an error otherwise.
Imperative mood, please: "Return an error".
qapi/misc.json line 1248
Quoted 7 lines
qapi/misc.json +2
-0# # Since: 1.1 # # Returns: nothing. # +# Note: prior to 3.2, this command does nothing in case the guest +# isn't suspended.
The next relase will be 4.0.
Quoted 15 lines
qapi/misc.json +1
-0+# # Example: # # -> { "execute": "system_wakeup" }qmp.c +2
-1@@ -183,7 +183,18 @@ void qmp_cont(Error **errp)void qmp_system_wakeup (Error **errp) { -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER ); +Error *local_err =NULL ; +
qmp.c void qmp_cont(Error **errp) · line 197
Quoted 10 lines
qmp.c +10
-0+if (!qemu_wakeup_suspend_enabled ()) { +error_setg (errp, +"wake-up from suspend is not supported by this guest" ); +return ; + } + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_OTHER , &local_err); +if (local_err) { +error_propagate (errp, local_err); + }
Make that
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, errp);
See error.h's big comment:
* Receive an error and pass it on to the caller:
* Error *err = NULL;
* foo(arg, &err);
* if (err) { * handle the error...
* error_propagate(errp, err);
* }
* where Error **errp is a parameter, by convention the last one.
[...]
* But when all you do with the error is pass it on, please use
* foo(arg, errp);
* for readability.
Quoted 31 lines
qmp.c +0
-0}ObjectPropertyInfoList *qmp_qom_list (const char *path,Error **errp)vl.c +4
-2@@ -1754,11 +1754,13 @@ void qemu_register_suspend_notifier(Notifier *notifier)notifier_list_add (&suspend_notifiers, notifier); } -void qemu_system_wakeup_request (WakeupReason reason) +void qemu_system_wakeup_request (WakeupReason reason,Error **errp) {trace_system_wakeup_request (reason);if (!runstate_check (RUN_STATE_SUSPENDED )) { +error_setg (errp, +"Unable to wake up: guest is not in suspended state" );return ; }if (!(wakeup_reason_mask & (1 << reason))) {@@ -1788,7 +1790,7 @@ void qemu_register_wakeup_support(void) wakeup_suspend_enabled = true; } -static bool qemu_wakeup_suspend_enabled (void ) +bool qemu_wakeup_suspend_enabled (void ) {return wakeup_suspend_enabled; }
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
One more thing...
Quoted 69 lines · Markus Armbruster
Quoted 67 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }
Quoted 15 lines
Quoted 6 lines
hmp.c +0
-0void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +0
-0hw/acpi/core.c static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) · line 521
Quoted 9 lines
hw/acpi/core.c +3
-1@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque) {ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }
Leaks the error object when qemu_system_wakeup_request() fails.
If it cannot fail here, pass &error_abort.
If it can fail, but you want to ignore failure, pass NULL.
More of the same elsewhere.
[...]
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
Quoted 90 lines · Markus Armbruster
One more thing...
Quoted 69 lines · Markus Armbruster
Quoted 67 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }Quoted 15 lines
Quoted 6 lines
hmp.c +0
-0void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +0
-0hw/acpi/core.c static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) · line 521
Quoted 9 lines
hw/acpi/core.c +3
-1@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque) {ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }Leaks the error object when
qemu_system_wakeup_request()fails.
Quoted 3 lines
If it cannot fail here, pass
&error_abort.If it can fail, but you want to ignore failure, pass NULL.
Good point. I'll simply pass NULL to all callers that didn't care for the error prior to this change.
Thanks,
Daniel
Quoted 4 lines
More of the same elsewhere.
[...]
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
Quoted 91 lines · Daniel Henrique Barboza
Quoted 88 lines · Markus Armbruster
One more thing...
Quoted 74 lines · Markus Armbruster
Quoted 72 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +0
-0@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque)Quoted 8 lines
hw/acpi/core.c static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) · line 521
Quoted 8 lines
hw/acpi/core.c +3
-1{ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }Leaks the error object when
qemu_system_wakeup_request()fails.
Quoted 6 lines
Quoted 3 lines
If it cannot fail here, pass
&error_abort.If it can fail, but you want to ignore failure, pass NULL.
Good point. I'll simply pass NULL to all callers that didn't care for the error prior to this change.
Most times I saw QEMU code ignoring errors, it actually didn't expect any errors to happen and was supposed to be using &error_abort instead.
This makes NULL errp always look like a bug to be fixed. If you are sure you really want to ignore an error, I'd recommend adding a comment making your intention explicit.
Signature · 1 line
Eduardo
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
Quoted 91 lines · Eduardo Habkost
Quoted 90 lines · Daniel Henrique Barboza
Quoted 88 lines · Markus Armbruster
One more thing...
Quoted 74 lines · Markus Armbruster
Quoted 72 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +0
-0@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque)Quoted 8 lines
hw/acpi/core.c static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) · line 521
Quoted 8 lines
hw/acpi/core.c +3
-1{ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }Leaks the error object when
qemu_system_wakeup_request()fails.
Quoted 8 lines
Quoted 5 lines
Quoted 3 lines
If it cannot fail here, pass
&error_abort.If it can fail, but you want to ignore failure, pass NULL.
Good point. I'll simply pass NULL to all callers that didn't care for the error prior to this change.
Most times I saw QEMU code ignoring errors, it actually didn't expect any errors to happen and was supposed to be using
&error_abortinstead.
In this particular case, the existing code wouldn't be expecting errors because qemu_system_wakeup_request wasn't reporting any. Prior to this patch, the function would either change the runstate and notify the wake up event or fail silently.
The idea of the patch is to add the extra Error pointer into qemu_system_wakeup_request, so qmp_system_wakeup can propagate the runstate_check error back to hmp_system_wakeup, instead of duplicating this runstate verification inside qmp_system_wakeup (like I was doing in some earlier version). With this idea in mind, passing NULL in the errp of the remaining qemu_system_wakeup_request calls will not improve the existing usage or fix potential bugs, sure, but doesn't make it worse either.
I don't see any problems with re-evaluating every existing qemu_system_wakeup_request call and judge f qemu should error_abort out of it in case of error. It's just out of scope of this patch series, IMO.
Thanks,
Daniel
Quoted 5 lines
This makes NULL errp always look like a bug to be fixed. If you are sure you really want to ignore an error, I'd recommend adding a comment making your intention explicit.
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
Quoted 97 lines · Daniel Henrique Barboza
Quoted 96 lines · Eduardo Habkost
Quoted 95 lines · Daniel Henrique Barboza
Quoted 88 lines · Markus Armbruster
One more thing...
Quoted 74 lines · Markus Armbruster
Quoted 72 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +0
-0@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque)Quoted 8 lines
hw/acpi/core.c static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) · line 521
Quoted 8 lines
hw/acpi/core.c +3
-1{ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }Leaks the error object when
qemu_system_wakeup_request()fails.Quoted 3 lines
If it cannot fail here, pass
&error_abort.If it can fail, but you want to ignore failure, pass NULL.
Good point. I'll simply pass NULL to all callers that didn't care for the error prior to this change.
Quoted 7 lines
Quoted 7 lines
Most times I saw QEMU code ignoring errors, it actually didn't expect any errors to happen and was supposed to be using
&error_abortinstead.This makes NULL errp always look like a bug to be fixed. If you are sure you really want to ignore an error, I'd recommend adding a comment making your intention explicit.
I agree the "ignore errors" feature is widely abused. I don't agree with adding "I mean it" comments. I think the proper remedy is to flag abuses in patch review, and clean them up wherever we find them.
Quoted 19 lines
In this particular case, the existing code wouldn't be expecting errors because
qemu_system_wakeup_requestwasn't reporting any. Prior to this patch, the function
would either change the runstate and notify the wake up event or fail silently.The idea of the patch is to add the extra Error pointer into
qemu_system_wakeup_request,
soqmp_system_wakeupcan propagate therunstate_checkerror back tohmp_system_wakeup,
instead of duplicating this runstate verification insideqmp_system_wakeup(like I was
doing in some earlier version). With this idea in mind, passing NULL in the errp
of the remainingqemu_system_wakeup_requestcalls will not improve the existing usage
or fix potential bugs, sure, but doesn't make it worse either.
Quoted 5 lines
I don't see any problems with re-evaluating every existing
qemu_system_wakeup_request
call and judge f qemu shoulderror_abortout of it in case of error. It's just out of scope of
this patch series, IMO.
Okay. I asked you to eliminate the code duplication, and I don't want to punish your good deed there by demanding further cleanup. That said, further cleanup is always welcome :)
Re: [Qemu-devel] [PATCH for-3.2 v10 3/3] qmp hmp: Make system_wakeup check wake-up support and run state
Quoted 128 lines · Markus Armbruster
Quoted 96 lines · Daniel Henrique Barboza
Quoted 95 lines · Eduardo Habkost
Quoted 94 lines · Daniel Henrique Barboza
Quoted 88 lines · Markus Armbruster
One more thing...
Quoted 74 lines · Markus Armbruster
Quoted 72 lines · Daniel Henrique Barboza
The qmp/hmp command '
system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' fromvl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended.This means that
system_wakeupis silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it.Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all.
All this considered, this patch changes
qmp_system_wakeupto check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output ofsystem_wakeupin a guest that does not have wake-up from suspend support (ppc64):(qemu)
system_wakeup
wake-up from suspend is not supported by this guest (qemu)And this is the output of
system_wakeupin a x86 guest that has the support but isn't suspended:(qemu)
system_wakeup
Unable to wake up: guest is not in suspended state (qemu)Reported-by Balamuruhan S <[email protected]>Signed-off-by Daniel Henrique Barboza <[email protected]>--- hmp.c | 5 ++++- hw/acpi/core.c | 4 +++- hw/char/serial.c | 3 ++- hw/input/ps2.c | 9 ++++++--- hw/timer/mc146818rtc.c | 3 ++- include/sysemu/sysemu.h | 3 ++- migration/migration.c | 7 +++++-- qapi/misc.json | 8 +++++++- qmp.c | 13 ++++++++++++- vl.c | 6 ++++-- 10 files changed, 47 insertions(+), 14 deletions(-)hmp.c +4
-1@@ -1220,7 +1220,10 @@ void hmp_cont(Monitor *mon, const QDict *qdict)void hmp_system_wakeup (Monitor *mon,const QDict *qdict) { -qmp_system_wakeup (NULL ); +Error *err =NULL ; + +qmp_system_wakeup (&err); +hmp_handle_error (mon, &err); }void hmp_nmi (Monitor *mon,const QDict *qdict)hw/acpi/core.c +0
-0@@ -514,7 +514,9 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)static void acpi_pm_tmr_timer (void *opaque)Quoted 8 lines
hw/acpi/core.c static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) · line 521
Quoted 8 lines
hw/acpi/core.c +3
-1{ACPIREGS *ar = opaque; -qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER ); +Error *err =NULL ; + +qemu_system_wakeup_request (QEMU_WAKEUP_REASON_PMTIMER , &err); ar->tmr.update_sci (ar); }Leaks the error object when
qemu_system_wakeup_request()fails.Quoted 3 lines
If it cannot fail here, pass
&error_abort.If it can fail, but you want to ignore failure, pass NULL.
Good point. I'll simply pass NULL to all callers that didn't care for the error prior to this change.
Quoted 7 lines
Quoted 7 lines
Most times I saw QEMU code ignoring errors, it actually didn't expect any errors to happen and was supposed to be using
&error_abortinstead.This makes NULL errp always look like a bug to be fixed. If you are sure you really want to ignore an error, I'd recommend adding a comment making your intention explicit.
I agree the "ignore errors" feature is widely abused. I don't agree with adding "I mean it" comments. I think the proper remedy is to flag abuses in patch review, and clean them up wherever we find them.
Quoted 19 lines
In this particular case, the existing code wouldn't be expecting errors because
qemu_system_wakeup_requestwasn't reporting any. Prior to this patch, the function
would either change the runstate and notify the wake up event or fail silently.The idea of the patch is to add the extra Error pointer into
qemu_system_wakeup_request,
soqmp_system_wakeupcan propagate therunstate_checkerror back tohmp_system_wakeup,
instead of duplicating this runstate verification insideqmp_system_wakeup(like I was
doing in some earlier version). With this idea in mind, passing NULL in the errp
of the remainingqemu_system_wakeup_requestcalls will not improve the existing usage
or fix potential bugs, sure, but doesn't make it worse either.
Quoted 8 lines
Quoted 5 lines
I don't see any problems with re-evaluating every existing
qemu_system_wakeup_request
call and judge f qemu shoulderror_abortout of it in case of error. It's just out of scope of
this patch series, IMO.Okay. I asked you to eliminate the code duplication, and I don't want to punish your good deed there by demanding further cleanup. That said, further cleanup is always welcome :)
I agree! Let's see if we can get this series pushed first, then we can get back to all these new "ignore errors" we just added here.
Daniel